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lUnTTnn fiTaTss PATENT @rricn.

GEORGES \VITZ, OF ROUEN, FRANCE.

PROCESS 0F PATTERN-DYE!NG.

SPECIFICATION forming part of Letters Patent No. 309,016, dated December 9, 188%.

Application filed January 12, ISFS.

(No specimens.) Patented in France November 2!), 1852, No. 152,335; in Belgium December 9.

1882. No. 59,796; in England December It I S-2, No. 5,9H, and in Germany December 18, 1882, Ape-1,17%.

T0 at] whom it may cancer/2 Be it known that I, GEORGES \VITZ, a citizen of the French Republic, and a resident of Rouen, (Seine Infrieure,)France,have invented certain Improvements in Preparing Vegetable Fibers and Fabrics to Better Receive Dyes, of which the followingis a specification.

My invention relates to a method of treating or preparing vegetable fibers and fabrics, but particularly woven fabrics of cotton, in order to better fit them for rccrivin g the colors in dyeing and printing. The treatment to which the fabric is submitted according to my process converts the cellulose, in whole or in part, into what I call oxyccllulosc, which conversion is effected by the oxidation of the cellulose in the fiber treated. Oxycellulose is a substance represented by the formula C H O -that is to say, the action of the oxidizing agents I employ on the cellulose (0, H 0 of the vegetable fiber treated eliminates H but at the same time 2H0 are added by hydration. Vegetable fibers,whcn oxidized to such an extent that the cellulose they contain is converted into oxycellulosc, will receive the dyes better than when not so oxidized, and the effect produced on the fiber is permanent-that is to say, if the color be entirely removed by the usual dccolorizing agents and the fiber redyed, it will be found that the dye of like strength will produce the same depth of shade as at first.

In carrying out my invention I may employ it for converting the cellulose in the whole fabric into oxycellulose for producing a unifOIlll shade of color throughout; but I usually employ it for producing a figured fabric in two shades of the same color, one dark and the other light. In effecting this result I resort to both printing and dyeing, as I will now explain.

Suppose it is desired to produce upon a light-blue ground spots or figures of a much darker shade of blue. I take, for example, a cotton fabric, bleached or unbleached, and dip it in a cold solution of potassium bichromate and allow it to dry. I then take a solution of starch at about centigrade and dissolvein it a quantity of oxalic acid, the solution being maintained lukewarm. With this starch-paste I imprint, by any of the usual methods, the

figures on the fabric treated as above, and then allow it to dry. The fabric is then washed, and the parts to which the acidified starch-paste has been applied will be found converted into oxycellulose. The fabric is now dipped into a cold bath of methyleneblue and dried and finished in the usual way. It will now be found that the entire fabric has received the blue dye, but that the spots or figures which have been converted into oxycellulose are much darker than the ground.

By the above-dcscribcd mode one of the chemical reagents is applied by dipping the fabric in a bath, and the other by printing; but I may produce the same results by printing alone, as follows: l

I make a printingpaste composed of seven liters of mucilagc from gum-dragon of fifty grams per liter, to which are added six hundred and fifty grams potassium chlorate, two liters of boiling water, tcn cubic centimeters solution of hypovanadic chloride containing ten grams of vanadium per liter. At the moment of using add to the above three hundred and fifty cubic centimeters of chlorohydric acid of connncrcc, 21 Baume. This rnucilage is printed on or applied to the fabric by the ordinary methods, and the fabric dried at a temperature of 50 to centigrade. After drying the fabric may be purified by first passing it through a weak solution of chloro hydric acid, and it is then washed in water.

The dyeing is effected by dipping the fabric thus treated in a bath made from any dye or dyes of a basic cl1aractersuch as methyleneblue,niethyleneviolot, fuchsine, aniline greens and browns, phosphine, &c., or mixtures of the same. The spots or figures printed and converted into oxycellulose will be found several shades dark or than the ground, but of the same color.

If the whole fabric is to be treated. for the conversion of the cellulose into oxycellulose, I employ the following process:

I take one equivalent in grams of potas sium bichromate and make a saturated solution of the same with water at the ordinary temperature. To this solution I add hydrochloric or sulphuric acid in the proportion of one to two equivalents as compared to the bichromate. In this compound I immerse a fabric of cotton for about half an hour. The bath may be gently heated to produce a more energetic action, or the energy of its action may be retarded by diluting it with water. After its removal from the bath the cotton fabric is washed, thoroughly dried, and then dyed. The dye-bath may be cold or hot, and when the fabric is finished in the usual way the color will be found fast. The shade will depend upon the strength of the dye-bath employed.

-Whatever may be the oxidizing agents employed in my process for permanently converting the cellulose of the vegetable fiber into oxycellulose, care should be taken not to push the oxidation so far as to weaken the fiber, the object being to impart to the vegetable fiber or fabric dyeing qualities that it does not otherwise possess, and at the same time, to avoid injuring the fiber materially by carrying the oxidation too far, each dyer will be governed somewhat by the reagents he employs and the effects he wishes to produce. There is, happily, a considerable interval between the point of oxidation which effects the conversion of the cellulose and the point of oxidation that produces a material weakening of the fiber, and this renders extreme care unnecessary.

The simplest method of determining the proper duration of the treatment, strength of reagents, &c., for producing the proper effect on any particular vegetable fiber is to make a test with small bits of fabric, and when the correct result is attained make a note of the agents employed, proportions, time, &e. This is the mode I employ, and I find it satisfae tory. The practical examples given herein may be relied on to produce good results.

It would be impracticable for me in this specification to give all the oxidizing agents that might be employed, their proportions,

and the particular mode of treatment of every kind of vegetable fiber with each of these reagents. Every dyer will understand that slight variations will be necessary in the treatment of the dift'crentfibers flax, for example, requiring ordinarily somewhat less energetic action to convert it than cotton. Rameegrass, china-grass, &c., are converted more or less readily, according to the state of disaggregation of their filaments or fibers.

Having thus described my invention, I claim- 1. The herein-described mode of preparing fabrics made from vegetable fibers in order to produce by dyeing figures thereon of the same color as the ground, but of a different shade, which consists in applying to certain portions of the fabric, as by printing, oxidizing agents which will convert .the cellulose in those portions into oxycellulose, then drying, and then washing and dyeing, substantially as set forth.

2. The hereiirdescribed method of printing and dyeing textile fabrics in order to produce figures thereon ofthe same coloras the groundas blue, for exan1plebut of a different shade, which consists in first dipping the fabric in a solution of potassium bichromate and then drying it; second, imprinting figures upon the fabric so treated with a solution of starch at about centigradc, in which is dissolved a 

